THE CLADISTICS AND HIGHER CLASSIFICATION OF THE PIMPLIFORMES (HYMENOPTERA, ICHNEUMONIDAE)

The monophyly of the ichneumonid clade Pimpliformes is established and the phylogenetic relationships of the eight component subfamilies are resolved. The clade (Acaenitinae + (Diacritinae + (Cylloceriinae + (D iplazontinae + Orthocentrinae)))) is the sister-lineage to the clade ( Pimplinae + (Rhyssinae + Poemeniinae)). The Nearctic genus Cressonia D asch is transferred to the Diacritinae from the Orthocentrinae. Tribes are not recognized in the Acaenitinae as the Coleocentrini (sensu Tow nes, 1971) is paraphyletic with respect to the Acaenitini. The Cylloce riinae is recognized as comprising three genera, Cylloceria Schiodte, Allomacrus Forster and Sweaterella gen.n. The Orthocentrinae, includin g the Helictinae of authors, is shown to be monophyletic, but the latt er is clearly shown to be paraphyletic if the Orthocentrus genus-group is excluded. The Pimplinae comprises four monophyletic tribes: the De lomeristini, consisting of Delomerista Forster and Atractogaster Kriec hbaumer; the Perithoini trib,n., which includes only Perithous Holmgre n (= Hybomischos Baltazar syn.n.); the Pimplini, which includes the Th eronia genus-group as well as the Pimpla genus-group; and the Ephialti ni, which includes the Polysphinctini syn.n., a monophyletic group tha t previously rendered the restricted Ephialtini paraphyletic. The trib e Delomeristini is the sister-group to the clade (Ephialtini + (Perith oini + Pimplini)). The subfamily Poemeniinae is recognized as comprisi ng three tribes: the Pseudorhyssini (trib.n,) which includes the singl e Holarctic genus Pseudorhyssa Merrill; the Rodrigamini (trib.n,) whic h includes only the Costa Rican genus Rodrigama Gauld; and the Poemeni ini, The tribe Pseudorhyssini is the sister-group to the clade (Rodrig amini + Poemeniini). The phylogenetic interrelationships of the genera of Poemeniini are resolved. A new genus from South Africa, Guptella ( gen.n.) is described, and Achorocephalus Kriechbaumer is shown to be a synonym of Eugalta Cameron (syn.n.). The evolution of biological trai ts within the Pimpliformes is discussed with reference to the elucidat ed phylogeny, and zoogeographic patterns are outlined.